Electropneumatic brake



Nov. 11 1924..

T. H. THOMAS ELECTROPNEUMATIC BRAKE Filed Feb. 3, 1923 .5255 mumssfi umamwumm INVENTOR T'HoMAs HTHOMAS ATTORNEY Patented Nov. 11, 1924.

THOMAS H. THOMAS, OF EDGEWOOD, PENNSYLVANIA, ASSIG-NOR TO WESTINGHOUSE AIR BRAKE COMPANY, OF VIILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ELECTRO'PNEUMATIC BRAKE.

Application filed February 8, 1923. Serial No. 616,812.

To all whom in may concern:

Be it known that I, THOMAS H. T HoMAs, a citizen of the United States, residing at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Electropneumatic Brakes, of which the following is a specification.

This invention relates to electro-pneumatic brakes, and more particularly to an electro-pneumatic brake device adapted to be employed in connection with the locomotive type of brake controlling valve device known as the distributing valve device.

One object of my invention is to provide an interlock valve device to prevent undesired functioning of the pneumatic portion of the equipment when the electric portion is operating.

Another object is to provide means for cutting off communication from the distributing valve release pipe to the application cylinder of the distributing valve device when the electric portion acts to eifect an application of the brakes.

Other objects and advantages will appear in the following more detailed description of the invention.

In the accompanying drawing, the single figure is a central sectional view of a distributing valve device with my improved electro-pneumatic control. mechanism ap plied thereto.

The distributing valve device may comprise a casing 1 containing an application portion and an equalizing portion. The application portion may comprise an application cylinder 2 containing a piston 3, a release valve chamber 4-, containing a release slide valve 5, and an application valve chamber 6, connected by passage 7 to main reservoir pipe 8 and containing an application slide valve 9, the valves 5 and 9 being operable by piston 3.

The equalizing portion may comprise a piston chamber 10, connected to the usual brake pipe 11 and containing a "piston 12 and a valve chamber 13, connected by passage 14 to a pressure chamber 15 and containing a slide valve 16 operable by piston 12. An application chamber 17 is connected through passages 18 and 19 with the application cylinder 2.

The electric portion may comprise a casing 20 interposed as a filling piece between the chamber portion 21 and the valve casing 1. Contained in casing 20 is an interlock valve mechanism and electro-ma-gnets A and B. The interlock valve mechanism may comprise a piston 22 contained in piston chamber 23, a slide valve 24 operable by said piston and contained in valve chamber 25, a piston 26, contained in piston chamber 27, and a slide valve 28, operable by piston 26 and contained in valve chamber 29.

The electro-magnet A controls double beat valves 30 and 31 and the electro-magnet B controls double beat valves 32 and 33 and the operation of said valves by the magnets A and B controls the fluid pressure in the piston chambers 23 and 27.

It will be understood that an automatic brake valve device and an independent brake valve device will be employed, the independent brake valve being adapted to control the independent release of fluid from the application cylinder 2 by way of the distributing valve release pipe 34 and the direct supply of fluid to the application cylinder by way of the application cylinder pipe 35 and the automatic brake valve device having the usual positions of release, run ning, holding, lap, service, and emergency. The movement of the automatic brake valve device to its different pneumatic positions also controls electric contacts connected through electric circuits to the magnets A and B, so that in release, holding, and lap positions the magnet A is energized and magnet B deenergized; in running position, magnets A and B energized; in service position, the magnet A deenergized and magnet B energized; and in emergency position both magnets deenergized.

In operation, when the brake pipe is charged with fluid under pressure in the running or release positions of the auto matic brake valve, fluid is supplied from the brake pipe to the piston chamber 10 of the equalizing valve device and flows through the usual feed groove around the piston 12 to valve chamber 13 and also through passage 14: to pressure chamber 15.

Assuming the automatic brake valve in running position, the ma ets A and B will be energized 31 d the double beat valves controlled thereby will assume the positions shown in the drawing.

The double beat valve 31 being open, fluid under pressure is supplied from the main reservoir through pipe 8, passage 7, and

#- passage 36, past the valve 31 to passage 31, which leads to piston chamber 23. Fluid under pressure is also supplied from passage 36, through passage 38 to valve chamber 25, so that the fluid pressures on opposite sides )f the piston 22 are now balanced, permitting the spring 39 to hold the piston in its inner position, as shown in the drawing. The valve 33 being in open position, fluid from the main reservoir is supplied through passage 40, past the valve 33 to passage 41, which leads to piston chamber 27 and since fluid at main reservoir pressure is also supplied through passage 38 to valve chamber 29, the fluid pressures on opposite sides of piston 26 are balanced, permitting the spring 42 to hold the piston 26 in its inner position.

In this position of the pistons 22 and 26, the slide valves 24 and 2S establish communication from the distributing valve re lease pipe 34 to the application cylinder 2 4 through passage 43, cavity 44 in slide valve 24, passage 45, cavity 46 in slide valve 28. passage 47 cavity 48 in slide valve 16, and passages 18 and 19.

If it is desired to effect a service application of the brakes, the movement of the automatic brake valve to service position establishes electric connections so that the magnet B remains energized while the magnet A is deenergized. The magnet B being energized, fluid pressure is maintained in the piston chamber 27, so that piston 26 remains in its inner position. The deenergization of magnet A causes the valve 31 to seat and valves 30 to open, so that fluid is vented from the piston chamber 23 through passage 37 to exhaust port 49. Piston 22 is consequently shifted by fluid pressure in valve chamber 25 to its outer position, in which slide valve 24 establishes communication from the pressure chamber 15 to the application cylinder 2 through passage 14, passage 54, cavity 53 in slide valve 28, passage 52, cavity 51 in slide valve 24, passage 50 to application chamber 17, and thence through passages 18 and 19 to the application cylinder 2.

Fluid is then supplied from the pressure chamber 15 to the application cylinder 2 and piston 3 is operated to move the application valve 9 to its open position, in which fluid under pressure is supplied to the brake cylinder, through passage 55 and brake cylinder pipe 56. It will be noted that the movement of slide valve 24 cuts off communication to the distributing valve release pipe 34, so that the volume of this pipe is cut off and the volume open to the application piston 3 is limited to that of the application chamber 17 and the application cylinder- 2.

lVhile in the service application position of the automatic brake valve device, fluid is vented from the brake pipe 11 in the usual way, the movement of the piston 12 to service position is prevented, since the pressure in valve chamber 13 and in the pressure chamber 15 is reduced by flow to the brake cylinder as above described.

It will be noted that since the equalizing piston 12 is prevented from moving to service position when the brake pipe pressure is reduced by the reduction of pressure in the pressure chamber due to the functioning of the electric control, if for any reason, the electric mechanism should fail to func tion, then the reduction in brake pipe pressure caused by the movement of the brake valve device to service position will cause the usual movement of the equalizing pis ton to service position, in which slide valve 16 will function to supply fluid from the pressure chamber to the application cylinder 2, so that a pneumatic service application will then be obtained.

The brakes may be released by moving the automatic brake valve to running position in which the distributing valve release pipe 34 is connected to the exhaust. Both magnets A and B being energized in the running position, both of the interlock pistons 22 and 26 will assume their inner positions and communication will be established from the application cylinder 2 to the distributing valve release pipe, as hereinbefore described, so that fluid is released from the application cylinder through the exhaust port of the automatic brake valve. The application piston 3 will then move to release position, in which fluid is released from the brake cylinder by way of the release valve The release of the brakes may be graduated by moving the automatic brake valve to running position as above described, and then when the desired reduction in brake cylinder pressure has been produced, the brake valve is turned to release position. In this position, the magnet A remains energized while the magnet B is deenergized. The deenergization of magnet B causes the valve 33 to seat and the valve 32 to open, so that fluid is vented from piston chamber 27 through passage 41 to exhaust port 49. The piston 26 is consequently shifted to its outer position by the fluid pressure in valve chamber 29, so that slide valve 28 is moved to out off con'nnunication from the application cylinder 2 to the distributing valve release pipe 34. The further exhaust of fluid from the application cylinder 2 is thus cut oil and the application piston 3 then moves to lap position, holding the pressure remaining in the brake cylinder,

In the release position of the automatic brake valve, fluid under pressure is supplied to the brake pipe, so that the brake pipe pressure is restored and the pressure chamber is recharged to the pressure carried in the brake pipe.

Upon movement of the automatic brake valve to emergency position, both magnets A and B are deenergized, so that the corresponding double beat valves operate to vent fluid from both piston chambers 23 and 27 and thus both pistons 22 and 26 are shifted to their outer positions. In emergency position, the brake valve device operates to vent,fluid from the brake pipe so that the piston 12 of the equalizing portion of the distributing valve device is shifted to emergency position, in which fluid is supplied from the pressure chamber 15 to the application cylinder 2 and the application piston 3 is thereupon actuated to eiiect the supply of fluid under pressure to the brake cylinder.

When a locomotive equipped with the hereinbefore described electro-pneumatic brake control is employed on trains which are not equipped for electric control and the brakes are to be controlled pneumatically and when the electric circuits fail for any reason, the magnets A and B being deenergized, as in emergency, the pistons 22 and 26 will be maintained in their outer positions as hereinbefore described and in order to maintain communication from the application cylinder 2 to the distributing valve release pipe 34, sothat the brakes on the locomotive may be independently released, an additional passage 57 leads to the seats of the interlock slide valves 24 and 28, so that when the pistons 22 and 26 are in their outer positions, the distributing valve release pipe 34 is connected to the application cylinder 2 through passage 43, cavity 44 in slide valve 24, passage 57, cavity 46 in slide valve 28, passage 47, cavity l8 in slide valve 16, and passages 18 and 19.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In an electro-pneumatic brake, the combination with electrically controlled mechanisms, of means operative upon energizati'on of one mechanism and the deenergization of the other mechanism to establish communication through which fluid under pressure is supplied to effect an application of the brakes and operative upon deenergization of both mechanisms for closing communication through which fluid is supplied to effect an application of the brakes.

2. In an electro-pneumatic brake, the combination with two valve devices for jointly controlling communication through which fluid under pressure is supplied to eiiect an application of the brakes, of separate electrically controlled means for controlling the operation of each valve device.

3. In an electro-pneumatic brake, the combination with two valve devices for jointly controlling communication through which fluid under pressure is supplied to effect an application of the brakes, of separate electrically controlled means for controlling the operation of each valve device, communicationthrough which fluid is supplied being established upon deenergization of one electrically controlled means while the other electrically controlled means is energized.

4. In an electro-pneumatic brake, the combination with two valve devices having positions for jointly establishing communication through which fluid under pressure is supplied to eflect an application of the brakes, and in which communication through which the brakes are released is cut off, of electrically controlled means for operating said valve devices.

5. In an electro-pneumatic brake, the combination with a valve device having a position in which communication is established through which fluid under pressure is supplied to effect an application of the brakes and a valve device having a position in which communication through which fluid under pressure is supplied to effect an application of the brakes is closed and communication through which the brakes are released is cut off, of electrically controlled means for operating said valve devices.

6. In an electro-pneumatic brake, the combination with a valve device having a position in which communication is established through which fluid under pressure is supplied to eflect an application of the brakes and in which communication through which the brakes are released is closed and a valve device having a position in which communi cation through which fluid is supplied to effect an application of the brakes is closed and communication through which the brakes are released is cut ofl, of electrically controlled means for operating said valve devices.

7. In an electro-pneumatic brake, the combination with two valve devices for controlling communication through which fluid under pressure is supplied to eflfect an application of the brakes, of separate electrically controlled means for controlling the operation of each valve device, said valve devices being movable to positions for establishing communication through which fluid is supplied to effect an application of the brakes upon deenergization of one electrically controlled means while the other is energized and adapted to out off said communication when both electrically controlled means are deenergized.

8. In an electro-pneumatic brake, the combination with two valve devices for jointly controlling communication through which the brakes are released, of separate elec trically controlled means for controlling the operation of said valve devices, said valve devices being movable to establish communication through which the brakes are released upon energization of both electrically controlled means and also upon deenergization of said electrically controlled means.

9. In an electro-pneumatic brake, the combination with two valve devices for controlling communication through which the brakes are applied, of separate electrically controlled means for controlling the opera tion of each valve device and operative upon deenergization of both electrically controlled means for cutting off communication through which the brakes are applied.

10. In an electro-pneumatic brake, the combination with an application chamber and means operated upon an increase in pressure in said chamber for efiecting an application of the brakes, of a pipe through which fluid is released from said chamber by operation of a brake valve device and electrically controlled means for controlling comn'iunication through said pipe.

11. In an electro-pneumatic brake, the combination with an application chamber and means operated upon an increase in pressure in said chamber for effecting an application of the brakes, of two valve devices for jointly controlling communication through which fluid is supplied to said chamber and electrically controlled means for controlling the operation of each valve device.

12. In an electro-pneumatic brake, the combination with an application chamber and means operated upon an increase in pressure in said chamber for effecting an application of the brakes, of two valve devices for jointly controlling communication through which fluid is supplied to and released from said chamber and electrically controlled means for controlling the operation of each valve device.

In testimony whereof I have hereunto set my hand.

THOMAS H. THOMAS. 

